Wireless messaging services, such as text messaging, allow users to generate and send messages to other users within a wireless communications network. Typically, a text message is sent to a Short Message Service Center (SMSC) that stores the text message and attempts to send the message to the recipient. If the recipient is not available, the SMSC queues the message for a later retry attempt. This type of delivery system is commonly referred to as a store-and-forward delivery system.
SMS delivery is also characterized as a best effort delivery system. As such, there is no guarantee that a message will be delivered to the intended recipient or that the message will be delivered at a certain time. In some instances the message is lost and never sent to the recipient.
Multimedia Messaging Service (MMS) allows users to exchange multimedia communications between capable mobile phones and other devices. MMS is an extension of the SMS protocol that defines a way to send and receive messages that include images, audio, and video in addition to text.